您好,欢迎访问三七文档
当前位置:首页 > 商业/管理/HR > 营销创新 > 2014年5月11日托福阅读真题
日托福阅读真题智课网整理机经词汇:pertinent=relevantaccrodingly=correspondinglyenormousl=hugecluter=groupinevitable=certainsimultaneously=atthesametimesubdue=defeatjustify=?coincidewith=?presumable=?第一篇:版本1:文章先讲太阳系里的东西都有相同的起源。先是说所有的东西是在一起的,然后说地球由于地表的水、火山活动和一个什么过程使得地球连最古老的石头都没有了。所以只能测定月球的陨石的成分了,结论是月球的表面和陨石的时间都是46亿年。因为月球表面没有地球的这些活动,所以可以测定。后面又说宇宙的星系都在不断地拉开距离,通过星系的红移可以确定距离还有速度,发现宇宙一直在膨胀。发现宇宙在137亿年前是一个点。然后就有了宇宙大爆炸。版本2:讲地球和宇宙年龄的测量。先说太阳系大部分物质是同一时间形成的,然后说地球年龄难是因为谁腐蚀。接着引入一种物质,可以通过同位素测年龄。结果是和月球上的最古老的石头近似。然后说宇宙在膨胀,大爆炸。通过红移测年龄。版本3:天文类,某种地球上的物质和月球上最古老的物质证明他。都始于自4.6million年前,于是证明太阳系的年龄是4.6Millionyears.另外还有种通过判断各星球一种wavelength的大小推断出他们在多少年前都是从个spot发展出来,于是判断了bigbang的时间。词汇:origin起源波长解析:天文主题文章的词汇专业性较强,需要提前对相关专题的TPO文章的生词熟悉,尽量减少生词恐惧带来的内耗。另外,出现天文理论的文章,结构通常都会比较清晰,但要着重识别对理论内容的态度倾向。相关背景:a.BigBangTheBigBangtheoryistheprevailingcosmologicalmodelfortheearlydevelopmentoftheuniverse.Accordingtothetheory,theBigBangoccurredapproximately13.82billionyearsago,whichisthusconsideredtheageoftheuniverse.Atthistime,theuniversewasinanextremelyhotanddensestateandwasexpandingrapidly.Aftertheinitialexpansion,theuniversecooledsufficientlytoallowtheformationofsubatomicparticles,includingprotons,neutrons,andelectrons.ThoughsimpleatomicnucleiformedwithinthefirstthreeminutesaftertheBigBang,thousandsofyearspassedbeforethefirstelectricallyneutralatomsformed.ThemajorityofatomsthatwereproducedbytheBigBangarehydrogen,alongwithheliumandtracesoflithium.Giantcloudsoftheseprimordialelementslatercoalescedthroughgravitytoformstarsandgalaxies,andtheheavierelementsweresynthesizedeitherwithinstarsorduringsupernovae.b.AcceleratinguniverseTheacceleratinguniverseistheobservationthattheuniverseappearstobeexpandingatanincreasingrate.Informalterms,thismeansthatthecosmicscalefactorhasapositivesecondderivative,[1]sothatthevelocityatwhichadistantgalaxyisrecedingfromusshouldbecontinuouslyincreasingwithtime.[2]In1998,observationsoftypeIasupernovaealsosuggestedthattheexpansionoftheuniversehasbeenaccelerating[3][4]sincearoundredshiftofz~0.5.[5]The2006ShawPrizeinAstronomyandthe2011NobelPrizeinPhysicswerebothawardedtoSaulPerlmutter,BrianP.Schmidt,andAdamG.Riess,whoin1998asleadersoftheSupernovaCosmologyProject(Perlmutter)andtheHigh-ZSupernovaSearchTeam(SchmidtandRiess)discoveredtheacceleratingexpansionoftheUniversethroughobservationsofdistant(High-Z)supernovae.[6][7][edit]Thesimplestevidenceforacceleratingexpansioncomesfromthebrightness/redshiftrelationfordistantType-Iasupernovae;theseareverybrightexplodingwhitedwarfs,whoseintrinsicluminositycanbedeterminedfromtheshapeofthelight-curve.Repeatedimagingofselectedareasofskyisusedtodiscoverthesupernovae,andthenfollowupobservationsgivetheirpeakbrightnessandredshift.Thepeakbrightnessisthenconvertedintoaquantityknownasluminositydistance(seedistancemeasuresincosmologyfordetails).Forsupernovaeatredshiftlessthanaround0.1,orlighttraveltimelessthan10percentoftheageoftheuniverse,thisgivesanearlylinearredshift/distancerelationduetoHubble'slaw.Atlargerdistances,sincetheexpansionrateoftheuniversehasgenerallychangedovertime,thedistance/redshiftrelationdeviatesfromlinearity,andthisdeviationdependsonhowtheexpansionratehaschangedovertime.ThefullcalculationrequiresintegrationoftheFriedmannequation,butthesignofthedeviationcanbegivenasfollows:theredshiftdirectlygivesthecosmicscalefactoratthetimethesupernovaexploded,forexampleasupernovawithameasuredredshiftimpliestheUniversewasofitspresentsizewhenthesupernovaexploded.Inanacceleratinguniverse,theuniversewasexpandingmoreslowlyinthepastthantoday,whichmeansittookalongertimetoexpandfrom2/3to1.0timesitspresentsizecomparedtoanon-acceleratinguniverse.Thisresultsinalargerlight-traveltime,largerdistanceandfaintersupernovae,whichcorrespondstotheactualobservations:whencomparedtonearbysupernovae,supernovaeatsubstantialredshifts0.2-1.0areobservedtobefainter(moredistant)thanisallowedinanyhomogeneousnon-acceleratingmodel.Corroboration[edit]Aftertheinitialdiscoveryin1998,theseobservationswerecorroboratedbyseveralindependentsources:thecosmicmicrowavebackgroundradiationandlargescalestructure,[8]apparentsizeofbaryonacousticoscillations,[9]ageoftheuniverse,[10]aswellasimprovedmeasurementsofsupernovae,[11][12]X-raypropertiesofgalaxyclustersandObservationalH(z)Data.[13]Explanatorymodels[edit]Modelsattemptingtoexplainacceleratingexpansionincludesomeformofdarkenergy,darkfluidorphantomenergy.Themostimportantpropertyofdarkenergyisthatithasnegativepressurewhichisdistributedrelativelyhomogeneouslyinspace.Thesimplestexplanationfordarkenergyisthatitisacosmologicalconstantorvacuumenergy;thisleadstotheLambda-CDMmodel,whichhasgenerallybeenknownastheStandardModelofCosmologyfrom2003throughthepresent,sinceitisthesimplestmodelingoodagreementwithavarietyofrecentobservations.Alternatively,someauthors(e.g.Benoit-Lévy&Chardin[14],Hajdukovic[15],Villata[16])havearguedthattheuniverseexpansionaccelerationcouldbeduetoarepulsivegravitationalinterac
本文标题:2014年5月11日托福阅读真题
链接地址:https://www.777doc.com/doc-2964105 .html